Syncing files between two computers

I apologize that this is probably the wrong place to post this, but I have always had just one computer until now.  Now that  I have two, what is the best way to access files from both of them?  I don't really want to keep them on OneDrive or something because I have more than the free account would allow, plus I already have my current computer backing up to a cloud backup.  Ideally, I would like the files to be stored on both computers but have them sync together so I always have the most updated version on whichever computer I use.  What do you guys do?